The present invention relates generally to adjustable support racks and, more particularly, to an adjustable rack for supporting firestop material in openings in walls, floors, ceilings, or the like.
One mechanism by which fire may spread from one compartment of a structure to another is through passages or openings, often referred to as through-penetrations, in floors, walls, ceilings, or the like. Such openings include, for example, cable access holes through which signal and power transmission cables pass.
Current methods used to prevent the spread fire and passage of smoke through such openings include cutting two intumescent sheets to follow the contour of the penetrating cables and providing a bead of moldable intumescent putty along the perimeter of each sheet. While this technique is generally satisfactory for resisting the spread of fire and preventing the passage of smoke from one compartment to another, installation is labor intensive and time consuming. Firetops fabricated in this manner also do not lend themselves to repeated re-entry for inspection, do not allow additional cables or wires to be run through the opening, and do not allow cables to be easily removed from the opening. To remove cables, for example, the intumescent material must be completely removed, discarded, and replaced with new intumescent material.
Techniques for fire stopping through-penetrations are also known in the prior art. The U.S. patent to Spencer U.S. Pat. No. 4,496,790 for example, discloses a self-anchoring poke-thru wiring device for the extension of communication and/or electrical wiring through a passage in a floor designed to prevent the spread of fire from one side of the floor to the other, and facilitate ready installation and removal of the device from above the floor opening. The device includes a pair of upper conduit portions aligned with a pair of lower conduit portions and a plurality of fire resistant expandable disks retained between an upper and lower plate intermediate the pairs of conduit portions, the disks and plates including aligned apertures with the conduit portions providing separate wireway channels.
These prior devices or techniques, however, suffer from certain drawbacks or shortcomings. Accordingly, there exists a need in the industry for a support rack for supporting intumescent material in through-penetrations which can be adjusted to fit in through-penetrations of various sizes, can be quickly and easily installed in the through-penetration, can be adjusted to provide maximum coverage of the open area around cable bundles of various sizes, is mechanically stable at temperatures typically encountered in a fire, and is inexpensive to produce.
The present invention provides an adjustable support rack for supporting firestop material in a through-penetration including a frame sized to fit within the through-penetration, at least one adjustable support member movably connected with the frame for supporting firestop material, and an adjustable mounting mechanism connected with the frame for securing the frame within the through-penetration. Firestop material refers to intumescent, endothermic, and ablative materials useful in resisting the spread of fire and smoke from one compartment of a structure to another.
In one embodiment, the support rack frame further includes a first side portion having a first end and a second end, a second side portion having a first end and a second end, and a generally rigid connecting portion extending between the first and the second side portion first ends, wherein the first and second side portions are arranged generally parallel and the connecting portion is arranged generally perpendicular to each of the first and second side portions, and further wherein the first side portion, the second side portion, and the connecting portion define an adjustably open support area, and each support member is movable within the open support area.
In one aspect of the invention, the support member comprises a plurality of support rods extending between and movably connected with the first and the second side portions. In another aspect of the invention, each of the first and second side portions includes a guide rail containing a plurality of aligned notches which receive ends of the rods and thereby serve to retain the rods at specific locations along the guide rails.
The adjustable mounting mechanism preferably includes a first fixed extension extending outwardly from the first side portion, a first latch slidably retained within the first side portion operatively associated with the first extension, a second fixed extension extending outwardly from the second side portion, a second latch slidably retained within the second side portion operatively associated with the second extension, each latch having a retracted position wherein the latch is arranged in close relation to its associated extension, and an actuated position wherein the latch is arranged away from its associated extension for engagement with the through-penetration, thereby to securely mount the support rack in the through-penetration. The adjustable mounting mechanism may also include a locking mechanism to prevent the device from accidentally releasing.
In another embodiment, the adjustable mounting mechanism includes a manually operable threaded device, such as a thumb screw or turnbuckle, capable of engaging the through-penetration with sufficient force to securely hold the support rack in place.
In another aspect of the invention, the support rack includes at least one extension attached to each of the front, back, and/or sides of the support rack to allow through-penetrations having cross-sectional shapes and sizes different from the support rack to be covered more completely. The extensions are removably connected with and extend outwardly from the front, back, or sides of the frame to allow the support rack to be sized for different sized through-penetrations.
The support rack is formed of a material that is mechanically heat stable at temperatures typically encountered in a fire and preferably to at least about 1500xc2x0 F., more preferably to at least about 1700xc2x0 F., and most preferably to 2000xc2x0 F. One suitable material is 0.150 inch cold rule steel rod. In one embodiment, the material is electrically nonconductive. In another embodiment, the support rack is provided with a non electrically conductive coating such as a paint, powder, and insulating resin.
In another aspect of the invention, the support rack includes an enclosure arranged over the upper surface of the support rack which encloses and protects the firestop material arranged on the support rack, thereby ensuring the system will withstand the water pressure exerted by a hose stream and meet the criteria set forth in ASTM E814.
The present invention also provides a method of fire stopping a through-penetration in a wall, floor, ceiling, or the like comprising the steps of providing an adjustable support rack including support members movable within an open area of the support rack for supporting firestop material in the through-penetration, mounting the support rack in the through-penetration, arranging the support members to maximize coverage of the open area, and arranging firestop material on the support rack. The method may further include providing an enclosure over the firestop material.